Production of concrete piles



.lune 27, 1950 A. B. HOLMES 2,512,831

PRODUCTION OF CONCRETE PILES Filed Feb. 25, 1948 5 Sheets-Sheet 1 FIGA.

www

FIG l June 27, 1950 A. B. HOLMES PRODUCTION OF CONCRETE PILES 5 Sheets-Sheet 2 Filed Feb. 25, 1948 .QUE

Aftor'my June 27, 1950 A. B. HOLMES PRODUCTION 0E CONCRETE PILES Filed Feb. 25, 1948 5 Sheets-Sheet 5 c/ Affar'ney.

June 27, 1950 A. B. HOLMES 2,512,831

PRODUCTION OF CONCRETE PILES Filed Feb. 25, 1948 5 Sheets-Sheet 4 Attorney` June 27, 1950 A. B. HOLMES PRODUCTION oF CONCRETE PILES 5 Sheet`s-Sheet 5 Filed Feb. 25, 1948 Patented June 27, 1950 STATES? PT'EPNT UFFICIE 2,512,831r v PRoDUcTioN oF coNCRirrEfPILES' Arthurf-Brannam-Holmes, Kingston-upon-Hull;` England* Applicationreiiruary 25, 1948; serial No; laissa InJGreat Britain IEebruaryy 26,1947

9 claims. (01561-57)l`v This invention concerns; the formation of lconcrete piles;l

One object of thepres'enty invention iste-pera mit of the formation'ofxa pile having an increased orpredetermine'd set,, iz'e. resistance to displace-- mentv by application of--Weight=-thereto; A furL ther object is to'provide arpile/ whichlisexpanded whilstfin the ygrounvd'rso:tighteningthe:groundand therebyincreasing the valuefof the skinfrictionand baser loading'. properties' of? thef pile.- Al fur"- thero-bject: is tov consolidate; ay column off con-jr crete whilst-at the same time-reducingthe possi-j bility of'..waisting 'at'.vari'ous pointsv inr the col-1 umnwhich can occur. when a piledsfor-med-'by any of the techniques now in common use.\` A further." object is tot: provide: a simplified-i` method whereby a pile may bee-constructed without=the permanent inclusionrtherein' of metal 4reinforcement means and yetrfwhichxis adaptedA towwfithstand'greatpressure.V A'further object is-to-pro videa pile` which is capablefofzwithstandingfa heavy loading using relatively;4 lightv equipment. A further objectds'to improve-the" state of the art.

These and other objects,v are accomplished according 1 to the" presentv invention` wherein a methodl of 1 forming' aconcrete pile.` includes f the steps of disposing'a solid body'permanentlyfat. or adjacent to' the bottom ofy afbore-,ffor apile,-or partiallyA completed-pile, chargingythe: bore with concrete, withdrawing: anyf drive Atubeor line-r used" when'- makingy the bore andv consolidating and radially i expanding: thef columnof 'concrete introduced 'into thebore ofl the lpile'wbymeans -of a'drive feed tube `ttedlwith'a preferablydetachable compressionmember.at its lovverend; the axial alignment of the saiddrive'feed tube* and compression member. Within thefborefiof.- thefpile beingcontrolled by; guide: meansfpermanentlywor temporarily: located: within fthe.- bore ofi the ypile and '-positively engagingi with the upperwsurface of the aforesaidsolidbody."

In one formt of theirinvention- Whereinfg-uide means for the' drive' feed tube@ are-permanently disposed ywithin tlfierpilei and. serve ase-aireinforcementi amethodi of forming fa reinforced :concrete pile'fcomprises 2 making'v a bore with or. without the aid' off ai. lining or: driving tube@` locating a retieula'randV tubular, .preferably;t a generally? cy lindii'cal; reinforcement-'Within isaid borev yupon a hard standing, charging; the ybore4 with" concrete, withdrawingfany lining or driving tube employed and' effectingv consolidation' and radial `expansionof` 'the fconcrete' by A tamping 'or x vibrating a-` 4drive feed'tube providedwithA a detachable'shoe inv a generally Verticalrdirectionvwithin the-reticular reinforcement,` thefdrive` feed tube-being; adapted to be withdrawn at one or more consolidation stagesvleavin'g a'fsho'e perman'entlyfset within the pile after each-A withdrawal and being charged with1concreteat the end ofeach consolidationstage? but prior to withdrawal from' the reticular reinforcement: Ruptureofthev concrete shell formed" between* the wall of-`the-v bore' and the ret'i'cular reinforcement? due to fluid' seepage into an otherwise centrally located void is thereby obviated; y y

In a further embodimentoffthe inventionra method ofr constructing a concrete pileincludes the: step ofv consolida-ting ja-nd radially expanding thec'olumnoi"` concrete-introduced into the bore of" thepile-` at. any desired f' depth by meansof l a drive feed tube-havinga detachable compression member at'4 its lowerv endwhen nrst.l introduced into the-concretecolumn, the said'A drive feed twbebeing withdrawn a` shortdistance, relled completely With-concrete, sealedvv-andf retamped oni one` orr av succession of occasions as desired. The drive feed=-tube-mayconveniently/ be maintained iri'axial alignment with-the bore' of the pile by engagement with guide -meansfeither permanentlyorvtemporarily'located within ther-bore of'thefpiler -When'lling thedrive feedtube to obtain-a local radial lvexpansionat a selected point in the column: itis lpreferred to usen a. relatively wetfconcretesofas topreventthelower end. of the drive feed. tube.- becoming fouled Y with a hard cake of concrete. In thisfparticular embodiment of the'dnvention-it will be `appreciatedthatonly one compression member or shoe is required-for use ,-wtih L- the A driverfeed .tuba Each subsequent tampingioperation.is.effected by:A means ofthe drive feedetubewhieh is compltelyflledwith concrete before each" tamping operation'an'd therefore acts .as ifffit were a solid ram ro'dl'- If. aliner has been usedwheii vmaking the bore, this must lbe withdrawn prior tc' consolidat: ingf.:-the :concrete coluniii" by" means "off the" drive feedftubeand? shoe. Theldivefeed tube con; solidatesithe` column of `coricreteby radial eX-r pansion from the centre of the column of concrete outwardly. The expanded concrete keys into the earth walls of the bore, passing through any reticular reinforcement present.

It will be appreciated that the number of shoes employed depends on the solidity of the several strata through which the bore passes. If the bore is made in rm ground, one consolidation stage only may be necessary, thus leaving one shoe only in the pile. If the bore is made through soft ground which gives under the outward expansion of the concrete, several consolidation stages may be required, necessitating leaving a plurality of shoes in the pile.

It is preferred to use a drive feed tube, the diameter of which is approximately the same as that of the shoe detachedly secured thereto.y

One method of achieving this result is by the provision of an inwardly directedlannular flange di'sposed around the periphery of the shoe into which the drive feed tube engages. By such means, the area of contact between the tamping or vibrating means and the inside surface of the reticular reinforcement, if such be present, is relatively small and withdrawal of the drive feed pipe correspondingly facilitated. if

Generally speaking, it is preferred to' reduce the diameter of the drive feed pipe to a minimum commensurate with using a tube which does not bend or warp under the inuence of tamping blows applied thereto whilst at the same time being of a sufficient diameter to allow free feed of the concrete.

It will be appreciated that the shape of the drive feed tube compression member or shoe is not critical. The impact surface may be for example, at, hemispherical or conical. Within limits, the sharper the point of a conical impact surface, the less the power required to be delivered to the drive feed tube to ensure consolidation.

The permanently disposed solid body may b'e in the form of a conical shoe used for the initial drive. This shoe may have a spigot for engagement of a tube therewith near its outer periphery when a closed drive tube or liner is used for forming the bore of the pile. Both this shoe and the compression member engaging with the drive feed tube maybe made from cast iron or may be fabricated from steel or may be a pre-cast reinforced concrete or any like substance suciently strong to withstand the pressure.

In order that it shall be possible to effect a positive temporary engagement between the permanently disposed solid body and the guide means for the drive feed tube temporarily located within the bore of the pilethe upper surface of the permanently disposed solid body may be provided with one or more recesses. yIf a conical shoe is used the apex of the shoe forms a convenient means for locating the guide means. Alternatively, it may be found convenient to provide an annular recess on the inside surface of the said conical shoe by which guide means may be located.

The said guide means for the drivefeed tube and compression member temporarily located within the pile may conveniently bein the form of a metal rod or tube located centrally within the bore of the pile, the compression member being drilled centrally so as to be capable of sliding axially upon the said guide rod or tube. A guide rod or tube is preferably disposed within the drive feed tube but it will be appreciated that guide means may also be provided for the drive feed tube and compression member disposed outside the drive feed tube, i. e. between the latter and the walls of the Ibore. For example, two or more guide rods may be located in an annular recess in a conical shoe constituting the permanently disposed solid body and the compression member may be provided with two or more complementary rebated surfaces adapted to align themselves with the two or more guide rods.

When employing guide means for the drive feed tube and compression member which are located but temporarily within the bore of the pile it is found convenient to provide ancillary guide means for the drive feed tube in the shape of a bracket which is detachably secured to the top end of a guide rod or tube. The diameter of this said Ibracket is but slightly less than the internal diameter of the drive feed tube and serves to prevent any wobbling of the drive feed tube as it slides up and down the guide rod.

When employing a centrally disposed guide rod or tube the compression member consists of a conical shoe having a central drilling therein adapted to slide upon the said guide rod or tube. It is preferred to use a compression member of y'a smaller diameter than the diameter of the bore of the pile because by so doing a lm of concrete is disposed between the wall of the bore and the drive feed tube and this ensures that the drive feed tube is in a relatively clean condition when it is withdrawn from the bore at the end of each tamping operation.

When first charging the bore of the pile after the initial drive, and when first charging the drive feed tube before withdrawal after each tamping operation except the last, it is preferred to use a small quantity of dry concrete because this reduces the possibility of back pressure and increases driving resistance at the toe of the pile.

The invention as applied to the formation of a reinforced concrete pile will now be more particularly described by reference to the accom panying drawings in which- Figures .1 to 8 are vertical medial sections showing successive stages in the formation of a reinforced concrete pile.

A bore is formed in the usual way either by driving a tube II having a detachable shoe (not shown) or by boring with the use of tube II. A charge I2 of stiff plastic concrete is then introduced into the lower end portion of the bore.

A spiral reinforcement I3 having its lower end fixed to a disc shaped metallic anchor plate I4 is then inserted. The anchor plate I4 need not necessarily be attached to the lower end portion of the reinforcement. No anchor plate is required at all if a hard standing can be provided for the reinforcement either by a driving shoe previously used in conjunction with tube II and left at the bottom of the bore or if a rock stratum has been encountered.

The bore is then lled up with stiff plastic concrete I5 (Figure 4) and tube II' is withdrawn. A shoe I6 of external maximum diameter slightly less than that of the interior of the reinforcement is then placed inside the reinforcement on top of the concrete and a drive feed tube I1 of less diameter than that ofthe interior of the reinforcement is placed on the shoe and driven down through the plastic concrete column either by use of a drop hammer or vibratory hammer (not shown); Tamping or vibrating is continued-with consolidation` and compressing of the concrete until 'the position is attained wherein.. shoe. I6 :A abuts.` againstnthe anchoa plate f I4 (Figurei: or aisuitablefsetiis;obtained..

rlhe. reinforcements.. acts.; as.. a guide .l fon the: drive feedtube andiforfth'ei shoeiwhil'stnthe ree. inforcement. isi. itself: centralised; ini relatipn.;,.to;; thei concrete column:`

Dur-ingthe downward movement ofaftheishoes and drive-feed tube the concreteris.;entiende@y through i. the reinforcementl substantiallyneqnalh-i in.. all` directions.` filled-l withv a. concrete charge I 8i' (Figur 6).?,` tubee H1 is-then withdrawn; a: newashoezfl Siputflon teni ofi the. pile andf the operationlcf driving." e. peated as many.-.times4 as:A may bei. found;j necesa sary.

0n they final; iillingy oftheedrifve feednltubesai relativelyV Wet charge2.0e of'concreteiis;prefere... ably:v usedl This-V relativelyfweticoncretef is. advantageousin .easily filling. up .thevoid-:createdebyf the-drive feed tube after..the-.drive= feed;.ti1be basi been'withdrawnfor the last time butrit hasebeen; foundithat more .ecient .driving-and;.consolidate. ing: effect obtains-.itz stiffer orfdryereyconcretes charges are utilised in. the. earlierf stages; Itp'has; been foundv that. by: use; ofA thegfinventicnasg e.. ofthegravelzor other. aggregatein; the concrete si driven tothe outside periphery ofpthe plethele by providing a. coarse:l adhesive. surface yreadilyi adapted 'to key againstxthe earthwall,` f..

Whilst .itzis preferred to.-emp1oyxa tubular. rep-,- inforcement which is of l generally-fcylindrical;` shape, a. reinforcement:` off polygonal.. such:- as. squareshape may.. bef used; Thegreinfolcement: may be Whollyofhelical formathatz-isto say-*Without incorporating`r any. directly. vei'iicallyy extende ing members.

Areinforced concrete'pile'includingfaaplulaliy of-eshoesor solid-'zbodies of. a..:crcss-;sectQiiacomr; mensurate withv the diameter ci:the1-retilllein.re-A inforcement .is novel and; is included .W'ilhliithtf scope of. theinyention.'`

The invention. asparticularly. appliedia the; formation of.vr a. concretepile.; hayingvgno, penna?. nent: inclusion thereingof metal` reinforcement.

meanswill now. be more .particularlwdesrbd by?. 45.l

reference. to. the accompanyingg.l dravviries-A in,y

which: y

Figures. 9 to.- 16.-.are.. verticali... medial.. Sections showing successive.` stages. iin the fQlmlbQIl. Off. 2. concrete .-pile,

Figure 17' 1 is .a Vertical medial-.i` section; 13.ovv-ingi analternative iormoi guide-means, and., v

Figurez-l 8i is. a cross.sectionzonl .theline milf-e XVIII. of 1 Fig-ure. 17.v

A; bere 12 l .is :formed by, driving@ itllbeljzttedwith a..detachable.. conical shce.2.3.iatqits bot-ff tom end;- A.guide rod.2dg.of.any suitablefsec.-v tion is then.. placed rinside..the,=. tubes. andxiynr tralized on.. the conical. shoenattlfieg` bottom;off.;v the pile; concrete.I isI then@ introducedgtinto.: the;- dr-ive-tube after Which-the`- drive tubelis Withdrawn `(Figure 12).; All secondfconicali-shpefZla.. preferably of. smaller` diameter. thanF the; permav nently vdisposed conical shoe .,at.; thei.` bcttorn of.

the y pile and i havingufanholef 21'; drilledcentrallyf de;

throughit isfthen placedover thefguide .tube 24;". a bracket 2li-forming agtopgude ofslightlv m211111- top omheguide.tube-:ande .drivefieed time s then .placed-.oventhis bracket; andbroughihtofresir 7U,

TheA drive. feed i tube-.fis a then: 10.2.

Eil 7.5; ing.

withdrawn .leavineztheysecond shQeein-etheeconcrete.. columna. This tampin'g-.e .opeiiatien .isere-1f peat'edaas :oftenas desired intordenfte zconseldattw the:V columnl ofi; concrete (Eigurml) ntigthe'; endofflthe operationsgthe guidesradxis Withdrawn;-` (Figuref 16).'.y preierablyfy befere4 thee last l. @hetgeeofgconcrete.is:introduced.intthdriveffeed'Wb f.

paralleli@ init. Qrizthe miivsicleof;Y t. tubi/t.. Therds .eiserne-as eil-ide. I

3.-Wbi.cl1 S. nrovidedwithf a -p r ...e a. siidineengagement.: withgt` anotlierfe'mbediment Qfih more 3:5. having@ .solidflclofiyf;n lpermanently dispos ed'` attheA bottom tlfierteof.` is charged, with..

concrete efleandl the. driying.- tube .or ligr.. thenl withdrawn; l (not. ShOWnl- Aldrirefeed'- .tube 1.38.'. hayineadetacham-ecompression member.. 3.9 atll its loiyer-` endl` and Aaf sealing. can.. 4l; at.. its upper.

.f end, 'sfthen inlQduc-evdlintofthe columnoffcone.

crete... (Figure. 19.) and tamped. soasto... conf solidatezandy radially kexpand the ;co1unmofcQn.-.- crete.. (Figure 20)..y Thedrivefeedtube isthen. Withdrawn Va shortdistance leayingtheccmpresfj g sionmember. t or .conicalshce 3S .permanently disposed inthe-pile.. The act .of vvithdrawalgleaves a; void 4|` at the-top..ofthe.drive feedjuhe (Fiere` ure- 2.1;).` The. can. 40 f is, removed, the drive. feed. tube wmplately.v refilled, the-'Cap replacedland the.l drive feed tube again4 tamped.;y This proce-y dure. Vis...repeated ,as .often as` `desired Iuntla local; ised; expansion 42..Qf the Concretecplumn at an Predetermineddepth is effected, (Figiireg2).; v

` It will; thus-.be seenv thatbymeans@ of .the present: invention afmetho'd Qf-fOYmiIieaOImrete pile.y is.glare/vid.ed.A in` which. relatively light yancil'-` laryfequiprnent. is, employed... By. consolidating a wllime. .of .concrete inthebore. off a pile.. Withouttheepresence of. any drive .tube or liner'and using a .drive .ieedtube.rnaintainedin.axialjalignL mentwithin thel saidboreLthe concrete isurged" outwardlyiromthe. centre of tliebore and-is thus* subjectedito radial expansion. Apile of-'rela tively uniform.. cross ,Y section may "beproducedLx o1j.ifY tampi11g.0perations are repeatedly carL minimum quantity 'only' of?l reinforcement ma-4 terial permanently 'disposed'fthereinr I declare that whatl'IffclaimT-isa" v f lj. A 'method of forming a concrete pile which comprises; combination; the-steps of disposing-i aj 'solide body--y permanently'l at* the '-botton'p-V of Y a,v b,orefor apile,v` disposing/guide meansL inthe'. bore of-thejv pile positivelyfengagingyvith thefselid-s body;- charging the:` bore;l Withaconcrete.: Withe drawing.` completely. any: drive= tube i `usediwheni makingthe.: bore.; so l as to.; leave :thee` concrete;v` in.. intimate; Contact:l with,the= Wallslf.:v of; .thee bere: throughoutlthe lengthfoffthe said bore; .ancbthcnf consolidating f `and. radially-:f expandingfthe.. col. umn .of concreteithroughout. tsijength .by means. ofi-"Tag: drive `-feediz' tubes;Vl frttedzgwithlideiahableg ccmpressiem membenzati its lcwereendz usine the; euideaamearis. for#l maintainingff-axi lignme tciithesaid ve ieedtubeandcemnressw briwh hfxbQlee Qfithey pile; dillngif .17a

zgsifaasr i of a drive feed tube fitted with a compressionmember at its lower end, using the guide means to maintain axial alignment of the said drive feed tube and compression member within the bore of the pile and finally withdrawing the guide means from the consolidated concrete column.

3 A method of forming a reinforced concrete pile which comprises, in combination, the steps of disposing a solid body permanently at the bottom of a bore for a pile, permanently disposing a reticular and tubular reinforcement within the bore, charging the bore with concrete, withdrawing completely any drive tube present from making the bore so as to leave the concrete in intimate contact with the walls of the bore throughout the length of the said bore, and then consolidating and radially expanding the column of concrete throughout its length by tamping a drlvefeed tube fitted with a detachable compression member at its lower end within the column face of the conical shoe, charging the bore with concrete, withdrawing completely the drive tube so as to leave the concrete in intimate contact with the walls of the bore throughout the length of the said bore, and then consolidating and radially expanding the column of concrete throughout its length by tamping a drive feed' tube fitted with a detachable compression member at its lower end within the column of`concrete, the guide means serving to maintain axial' alignment of the said drive feed tube and compression member within the bore of the pile during each tamping operation. f

5. A method of forming a concrete pile comprising, in combination, the steps of disposing a solid body having at least one recess in its upper surface permanently at the bottom of a bore for a pile, temporarily introducing into the bore at least one vertically disposed metal member adapted to engage within the said recess, charging the bore with concrete, withdrawing completely any drive tube used for making the bore so as to leave the concrete in intimate contact with the walls of the bore throughout the length of the said bore, and then consolidating and radially expanding the column of concrete by means of a drive feed tube fitted with a detachable compression member at its lower end, using the vertically disposed metal member to maintain axial alignment og the drive feed tube during each tamping opera on.

. 6. A ymethod of forming a .concrete pile comprising, in combination, the steps of disposing an inverted conical shoe permanently at the bottom of a bore fora pile, introducing a metal rod centrally into the bore of the pile and positively engaging said rod within the apexof the inverted conical shoe, charging the bore with concrete, withdrawing completely any drive tube used when making the bore 'so as to leave the concrete in intimate contact with the walls of the bore throughout'the length of the said bore, and consolidating and radially expanding the column of concrete throughout its length by tamping a drive feed tube tted with a detachable compression member at its lower end having a central passage therethrough adapted to slidably engage with the metal rod during each tamping operation.

"l, A method of forming a concrete pile comprising, in combination, the steps of disposing an inverted conical shoe permanently at the bottom of -a bore for a pile, locating a metal tube centrally within the bore of the pile so as to engage within' the apex of the inverted conical shoe, charging the bore with concrete, withdrawing completely 'anydrive tube used when making the bore so as to'leave the concrete in intimate contact with the walls of the bore throughout the length of the said bore, disposing a drive feed tube tted with a centrally drilled inverted conical shoe at its lower end in sliding engagement with the metal tube, temporarily securing a bracket to the top end of thev metal tube within the drive feed tube and consolidating and radially expanding the column of concrete throughout its length by the application of an axial vibratory movement to the drive feed tube.

8. A method of forming a reinforced concrete pile comprising, in combination, the steps of making'a bore for a pile with a drive tube fitted with an inverted conical shoe at its lower end, locating a reticular and tubular reinforcement within said bore so as to positively engage with the said inverted conical shoe, charging the bore with concrete, withdrawing completely the drive tube leaving the inverted conical shoe permanently disposed at the bottom of the bore so as to leave the concrete in intimate Contact with the walls of the borev throughout'the length of the said bore, consolidating and radially expanding the column of concrete throughout its length by tamping a drive feed tube provided with a detachable inverted conical shoe at its lower end in a generally vertical direction within and guided by the reticular reinforcement, withdrawing the driven drive feed tube after rst recharging it with concrete so as to fill up the void, leaving the inverted conical shoe permanently disposed within the bore of the pile, refitting the drive feed tube with a fresh inverted conical shoe and repeating the tamping operation a plurality of times.

9. A method of forlning a concrete pile comprising, in combination, the steps of disposing a solid body permanently at the bottom of a bore for a pile, disposing guide means for a drive feed tube within the bore of the pile positively engaging with the solid body, charging the bore with concrete, withdrawing completely any drive tube used when making the bore, consolidating and radially expanding the column of concrete by tamping a drive. feed tube within the column of concrete having a detachable compression member at its lower end when first introduced into the concrete column, withdrawing the drive feed tube a short distance, filling the voidA created at the top ofthe drive feed tube with fresh concrete,

sealing the top of the drive feed tube, and repeating the tamping operation successively so as to produce a localised expansion of the column of concrete at a predetermined depth, whilst utilising the guide means to maintain axial alignment of the drive feed tube during each tamping operation.

ARTHUR BRANNAM HOLMES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Blumenttal July 15, 1924 Number Number Number 

